Insects and Allies Associated With Bromeliads a Review

Mosquitoes and Bromeliads

Summary

Water from rainfall or irrigation can collect in the central tanks or axils of bromeliads planted equally ornamentals in subtropical and tropical gardens. The aquatic fauna that occupy these small pools in bromeliad axils and tanks often include the immature stages of mosquitoes. In Florida, mosquitoes that develop in this microhabitat include native species of Wyeomyia besides as the invasive container-generalist species Aedes albopictus and Aedes aegypti, which may transmit mosquito-borne viruses such as dengue and Zika to humans. Experiments conducted under semi-natural conditions in Florida using the popular ornamental bromeliad Billbergia pyramidalis showed that small larvae of A. albopictus were unable to complete development in the presence of large larvae of Wyeomyia spp., leading to the conclusion that competition with the non-vector native species provides a biological control of the unsafe, invasive vector musquito.

In 2016 during a Zika virus outbreak in Miami, ornamental bromeliads were removed from public gardens in the conventionalities that they contributed to product of the vector A. aegypti. Similarly, in 2008 during a dengue epidemic in Rio de Janeiro, municipal mosquito command workers extirpated bromeliads from private gardens to eliminate supposed sources of A. aegypti. Subsequent surveillance and identification of mosquitoes extracted from bromeliad tanks in an urban botanical garden in Rio revealed the presence of very few immatures of the vector species A. aegypti and A. albopictus, and currently there is no validation for the elimination of bromeliads during outbreaks of musquito-borne viruses.

However, fifty-fifty in the absence of vector-borne diseases, water-holding bromeliads may exist sources of nuisance bitter mosquitoes similar Wyeomyia spp. This publication provides recommendations for environmentally acceptable ways to control the production of nuisance mosquitoes in bromeliads, suggestions for planting species of bromeliads less probable to favor the production of mosquito-borne disease vectors, and full general advice nigh personal protection against mosquito bites.

Introduction

Due to their bonny leaf and flowers and ease of propagation, exotic tank bromeliads are pop ornamental landscaping plants in areas similar Florida with tropical and subtropical climates (Figure 1; Frank and Lounibos 2009). Unfortunately, tank bromeliads that agree water also frequently produce biting mosquitoes. Whether the mosquitoes produced by ornamental bromeliads are responsible for transmitting viruses to humans has been a source of international controversies during mosquito-borne virus outbreaks. This publication is intended for all audiences and provides background information on mosquitoes, bromeliads, their relationships, and the controversies that have taken place surrounding them. Recommendations for reducing the number of mosquitoes produced past bromeliads are as well provided.

Figure 1. Examples of exotic tank bromeliads commonly used for landscaping in south Florida.
Credit: E. A. Buckner and A. L. Romero-Weaver, UF/IFAS

Mosquitoes

There are more than 3500 species of mosquitoes worldwide, which can exist found on all continents except Antarctica. All mosquitoes possess a life cycle fabricated up of iv stages: egg, larva, pupa, and adult (Effigy 2). Mosquito eggs are laid singly or in rafts on the surface of water or on moist substrate. All mosquito eggs need water to hatch. The larval and pupal life stages are aquatic. Most mosquito larvae obtain nutrients past filter feeding on microorganisms and organic droppings in the water of their aquatic habitats. As mosquito larvae grow, they laissez passer through a total of four increasingly larger larval instars (stages). Once a musquito larva has obtained all the nutrition it needs, it transforms into a pupa, which is the mosquito equivalent of a butterfly's chrysalis. Pupae do non feed just can swim to avert predation. Adult mosquito characteristics form during the pupal stage, which ordinarily lasts 2 days. After the transformation is complete, a fully formed adult mosquito emerges from a slit in on the dorsal side of the pupa, leaving its pupal peel behind. The new adult musquito rests on the surface of the water briefly, and then flies abroad to begin the terrestrial phase of its life cycle. Both developed male and female mosquitoes feed on plant nectar as a source of carbohydrates for energy. Typically, after an adult female mosquito has mated with a male person, she volition bite and take one or more blood meals to finish egg evolution. If infected with a pathogen like a virus, protozoan, or nematode roundworm, the mosquito may transmit the pathogen to the host while claret-feeding (Figure 3).

Figure 2. Life cycle for Aedes aegypti, a container-inhabiting mosquito that may be found inhabiting water-property bromeliads during its aquatic, immature life stages.
Credit: Due east. P. Caragata, UF/IFAS

Figure 3. Transmission of mosquito-borne pathogens to people. The yellow dots in the image stand for a pathogen that tin be transmitted by mosquitoes to people.
Credit: A. L. Romero-Weaver, UF/IFAS

Bromeliads

Bromeliads are perennial flowering plants of the pineapple family Bromeliaceae. At that place are over 3,000 bromeliad species that are native primarily to the subtropical and tropical Americas (Benzing 1990, Holst and Luther 2004). Sixteen species are native to the land of Florida (Luther and Benzing 2009). For more information on Florida's native bromeliads, see https://edis.ifas.ufl.edu/publication/uw205. While a few exotic bromeliads similar pineapples are grown as crops, virtually are grown in tropical and subtropical climates for apply as ornamental landscaping plants due to their bonny leaf and flowers (Effigy one), inexpensiveness, and low maintenance (Frank and Lounibos 2009, Frank 2021). Bromeliads tin can also be grown in greenhouses or indoors in temperate climates (Figure 4).

Effigy four. Bromeliads growing in a greenhouse.
Credit: UF/IFAS

Many bromeliads are described every bit epiphytic, which means that they grow on other plants (Benzing 1990; Figure 5). The roots of epiphytic bromeliad plants help to anchor them to the plants or the surfaces that they grow on (Benzing 2000). Epiphytic bromeliads utilize trichomes (specialized hairs that cover their leaves) to absorb water and nutrients (Luther and Benzing 2009, N et al. 2013). Additionally, in most bromeliads, intricately arrayed leaves form a spiral rosette with a tank-like structure at its center where rainwater and debris tin collect (Figure 6). Water can likewise collect at the axil (base) of each bromeliad leaf (Ladino et al. 2019; Figure vii). The water-filled tanks and axils can trap pollen, dead leaves, twigs, and seeds falling from copse, which break downwardly to form a nutritive soup available to the bromeliads and other organisms inhabiting the bromeliads like mosquito larvae.

Figure 5. An epiphytic bromeliad native to Florida, the cardinal airplant, Tillandsia fasciculata.
Credit: L. P. Lounibos, UF/IFAS

Figure 6. Fundamental tank holding water and debris at the center of a spiral rosette formed by bromeliad leaves.
Credit: L. P. Lounibos, UF/IFAS

Figure vii. The giant airplant, Tillandsia utriculata, one of Florida'south native bromeliads, with its leaves cutting to show how h2o tin can collect at the axil (base) of each bromeliad leaf.
Credit: Durland Fish, Yale University

Can bromeliads produce mosquitoes?

Yes. H2o that collects in a bromeliad tank or at the axils of bromeliad leaves is an case of a phytotelm, a pocket-sized water body held past terrestrial plants, which tin be used by container-inhabiting mosquitoes for oviposition (egg laying) and pre-developed development (Figures 8 and 9). Container-inhabiting mosquitoes are chosen such because of the typically small-scale aquatic habitats that they occupy during their immature life stages. Container-inhabiting mosquitoes may be subdivided into generalist species, such as the invasive yellow fever mosquito (Aedes aegypti) and Asian tiger mosquito (Aedes albopictus), whose adult females can transmit chikungunya, dengue, and Zika viruses to humans, or phytotelm specialists, such equally the Florida native bromeliad-inhabiting mosquito species Wyeomyia vanduzeei and West. mitchellii, whose larvae are typically establish only in the axils of bromeliads (Kitching 2000, Frank and Lounibos 2008). For more data on Florida container mosquitoes, delight see https://edis.ifas.ufl.edu/publication/IN1315.

Figure eight. Water and musquito larvae in a tank bromeliad. Red arrows point to h2o collected at the axils (bases) of bromeliad leaves. Mosquito larvae are circled in blue.
Credit: J. Newman, UF/IFAS

Effigy ix. Musquito larvae in the water-filled central tank of a bromeliad.
Credit: L. E. Reeves, UF/IFAS

Practise all bromeliads produce mosquitoes that tin transmit viruses to humans?

No. Many factors including a bromeliad'due south location, species, and size tin influence the mosquito species institute within information technology (O'Meara et al. 2003). Raban (2006) establish that more Asian tiger mosquito eggs were laid in tanks of Neoregalia cruenta, an exotic bromeliad, in paired comparisons with similarly sized Billbergia pyramidalis, another tank bromeliad popularly grown in Florida. Likewise, as mentioned earlier, the mosquito species W. mitchellii and W. vanduzeei are phytotelm specialists, and their larvae are typically plant only in bromeliads. If abundant, Wyeomyia mosquitoes can be a biting nuisance to bromeliad growers and their neighbors, but they are not known to transmit viruses that cause diseases in humans (Edman and Haeger 1978). In fact, the presence of Wyeomyia mosquito larvae in bromeliads may actually reduce the number of yellow fever and Asian tiger mosquito larvae developing in them. Multiple surveys of the mosquito fauna in southern Florida demonstrated that immature stages of the yellowish fever mosquito or the Asian tiger mosquito were relatively uncommon if Wyeomyia mosquito larvae were abundant in the same bromeliad tanks or axils (Frank et al. 1988, Lounibos et al. 2003). For instance, Frank et al. (1988) surveyed mosquito larvae in the exotic bromeliad Billbergia pyramidalis in iv southern Florida cities and found approximately twenty,000 immature Wyeomyia mosquito larvae but less than 200 young yellowish fever mosquitoes. Conversely, Lounibos et al. (2003) documented a dramatic increase in Asian tiger mosquito abundance in exotic bromeliads due north of Orlando in central Florida where Due west. vanduzeei and Westward. mitchellii are rare due to the scarcity of their native bromeliad host plant Tillandsia utriculata. This inverse human relationship between Wyeomyia and Asian tiger mosquito larval abundances observed in bromeliads along a latitudinal slope in Florida suggests that Wyeomyia may inhibit the product of Asian tiger mosquitoes in exotic bromeliads (Lounibos et al. 2003).

Also, Lounibos et al. (2003) conducted experiments in tanks of B. pyramidalis bromeliads fix in semi-natural outdoor enclosures to determine whether mature larvae of Wyeomyia spp. (a) inhibited oviposition (egg-laying) by gravid (pregnant) Asian tiger mosquitoes or (b) impeded growth and development of early on-stage larvae of Asian tiger mosquitoes. Results clearly showed that Wyeomyia spp. larvae did not inhibit oviposition by Asian tiger mosquitoes in bromeliads, simply the large larvae of the native phytotelm specialists did inhibit survivorship and development of early-stage Asian tiger mosquito larvae. Thus, larval contest between native Wyeomyia mosquitoes and the invasive Asian tiger mosquito is thought to be the mechanism responsible for the changed human relationship in abundances of these mosquitoes in samples from bromeliads in southward and central Florida (Lounibos et al. 2003).

Controversies over mosquitoes and bromeliads during mosquito-borne virus outbreaks

In Rio de Janeiro, Brazil, dengue is an endemic and regular public health threat, especially during the rainy flavour. During a peculiarly fierce dengue epidemic in 2008, mosquito command authorities in Rio began to destroy exotic bromeliads in the gardens of residents, based on the untested hypothesis that xanthous fever mosquitoes, which transmit dengue virus to humans, were commonly produced in the tanks (Mocellin et al. 2009). To fill up a research gap on the relative importance of terrestrial bromeliads for producing yellow fever mosquitoes or Asian tiger mosquitoes in urban Rio, Mocellin et al. (2009) sampled the immature stages of mosquitoes monthly for i year from the tanks and axils of x bromeliad plants located in Rio'south Jardim Botanico, an old public garden located in relict Atlantic coastal rain forest bordered by favelas (slums) with regular dengue virus manual. Amid 2,816 immature mosquitoes identified from these samples, merely two yellow fever mosquitoes and 5 Asian tiger mosquitoes were detected. The majority of mosquito species identified were Culex (Microculex) and Culex (Culex), native, not-vector specialists of Brazilian bromeliads that might play similar roles as Wyeomyia spp. in Florida to minimize the product of invasive Aedes spp. generalists from these phytotelmata (small water bodies held by terrestrial plants). A plaque commemorating these enquiry findings was afterward erected in the Jardim Botanico (Figure 10). Additionally, working north of Rio in Vitoria, Santos et al. (2011) concluded from mosquito surveillance that bromeliads growing naturally on rocky outcrops almost houses with known dengue manual did non contribute to yellowish fever mosquito production.

Figure ten. A plaque commemorating the enquiry findings of Mocellin et al. (2009) on mosquito larvae found in bromeliads in Jardim Botanico in Rio, Brazil.
Credit: Fifty. P. Lounibos, UF/IFAS

Based on the concern that exotic bromeliads planted as ornamentals in public spaces in the city of Miami were producing yellow fever mosquitoes during the Zika outbreak of 2016, Miami-Dade Mosquito Command authorized the removal of hundreds of bromeliads (Gomez 2016). It remains controversial whether this action, undertaken to protect public health, was warranted. Elsewhere in Miami, subsequent surveillance of exotic bromeliad phytotelmata after the outbreak indicated that the xanthous fever mosquito was the virtually abundant species detected, being slightly more common than Wyeomyia spp. (Wilke et al. 2018). In other places within Florida, contempo surveillance of mosquito abundances in tanks and axils of exotic bromeliads showed that the Asian tiger musquito was the most prevalent species in samples in urban St. Augustine, followed by W. vanduzeeii (Xue et al. 2018). Unfortunately, larval densities, pupal numbers, and bromeliad species, all important for direction decisions based on the information, were not provided in these surveys.

Currently, information are insufficient to back up removal or destruction of tank bromeliads as a means of vector command directed at invasive yellow fever or Asian tiger mosquitoes. Before remedial deportment are applied to ornamental bromeliads that grade phytotelmata, researchers or vector control workers demand to first found that major numbers of these Aedes spp. vectors are developing to the pupal stage in these plants. Because native Wyeomyia spp. mosquitoes, which do not transmit pathogens to humans, exert a natural biocontrol outcome confronting yellow fever and Asian tiger mosquitoes, maintenance of these species in bromeliad tanks and axils should exist encouraged. More experimental inquiry is needed to define the conditions under which and mechanisms whereby Wyeomyia spp. specialists suppress Aedes spp. generalists in these container habitats.

Recommendations for Mosquito Control in Bromeliads

First and foremost, understand that bromeliads crave ongoing maintenance to foreclose production of mosquitoes! Though Wyeomyia spp. mosquitoes may not transmit harmful viruses every bit Asian tiger and xanthous fever mosquitoes can, they tin can bite humans and go a nuisance if in high numbers. Therefore, if you lot are unable to provide the ongoing maintenance necessary to forestall bromeliads from producing potential nuisance-causing mosquitoes, consider planting other plants with attractive foliage in your landscape.

Notwithstanding, if you are a bromeliad enthusiast and your landscape is fabricated upward of many tank-forming bromeliads, you can avoid the rapid production of mosquitoes in your backyard using one or a combination of these management recommendations:

1. Flush out eggs, larvae and debris accumulated in bromeliad axils and tanks using a potent jet of water from a hose at least one time a week.
2. Add larvicides to the water accumulated in the leaves of bromeliads. At that place are ii commercially available larvicide active ingredients, methoprene and Bacillus thuringiensis subspecies israelensis (commonly known as Bti), that can be institute in nigh home and garden supply stores. When applied correctly using instructions found on product labels, these larvicides do not impairment plants, people, pets, or the environment (CDC 2020). They are usually sold in granules or pellets in slow-release formulations, that tin can be added straight to the h2o in the plant. Please follow the manufacturer's label application instructions.
3. Consider planting ornamental bromeliads that might be less favorable habitats for unwanted immature mosquitoes. While appropriate experiments have yet to be washed that compare the suitability of popular bromeliad species as habitats for common pest and vector mosquitoes, some general communication is derivable from our current knowledge. Almost importantly, a large central tank that tin can hold abundant h2o for young mosquito growth and development is the characteristic most likely to favor generalist container mosquitoes, such as yellow fever, Asian tiger, or even southern firm. Therefore, gardeners worried about favoring pest or vector mosquito species in their thou might consider planting bromeliads with no or reduced cardinal tanks instead, such as Cryptanthus spp. or some species of Tillandsia.

Additionally, to prevent musquito bites, employ musquito repellent when working exterior, encompass your skin with long pants, long-sleeved shirts, and shut-toed shoes, and cover your doors and windows with screens to keep mosquitoes out of your home. A list of CDC-recommended active ingredients to look for when purchasing an effective mosquito repellent product can be found at

https://world wide web.cdc.gov/zika/prevention/foreclose-mosquito-bites.html.

References

Benzing, D. H. 1990. Vascular epiphytes. General biology and related biota . Cambridge, UK: Cambridge University Press.

Benzing, D. H. 2000. Bromeliaceae: Profile of an adaptive radiations . Cambridge, Britain: Cambridge University Press. p. 690.

Centers for Disease Control and Prevention (CDC). 2020. "Larvicides." August 24, 2020. Accessed February 25, 2021. https://www.cdc.gov/mosquitoes/mosquito-control/community/larvicides.html.

Frank, J. H. 2021. "Bromeliad Biota." Accessed April 21, 2021. https://entnemdept.ufl.edu/frank/bromeliadbiota/index.htm

Frank, J. H. and L. P. Lounibos. 2009. "Insects and Allies Associated with Bromeliads: A Review." Terrestrial Arthropod Review 1:125–153. doi: x.1163/187498308X414742.

Frank, J. H., J. P. Stewart, and D. A. Watson. 1988. "Mosquito Larvae in the Axils of the Imported Bromeliad Billbergia pyramidalis in Southern Florida." Florida Entomologist 71:33–44. https://journals.flvc.org/flaent/article/view/58346.

Gomez, A. 2016. "Miami'due south Beloved Shrub Is a Zika Breeding Ground." U.s.a.A. Today, September 12, 2016. Accessed Feb 18, 2021. https://www.usatoday.com/story/news/2016/09/12/zika-miami-bromeliad-mosquito-convenance-ground/90269966/.

Holst, B. K., and H. East. Luther. 2004. "Bromeliaceae (Bromeliad family)." In Flowering Plants of the Neotropics. Edited by N. Smith, S. A. Mori, A. Henderson, D. W. Stevenson, and S. V. Heald. Princeton: Princeton University Press; Princeton, New Jersey, U.S.A: pp. 418–421.

Kitching, R. 50. 2000. "Food Webs and Container Habitats: The Ecology and Natural History of Phytotelmata." Cambridge University Printing, Cambridge, England.

Lounibos, L. P., G. F. O'Meara, and Northward. Nishimura. 2003. "Interactions with native mosquito larvae regulate the production of Aedes albopictus from bromeliads in Florida." Ecological. Entomology 28:551–558. doi: ten.1046/j.1365-2311.2003.00543.x.

Luther, H. Eastward., and D. H. Benzing. 2009. Native Bromeliads of Florida. Pineapple Printing Inc. Sarasota, Florida.

Mocellin, M. G., T. C. Simões, T. F. Silva do Nascimento, K. Fifty. F. Teixera, Fifty. P. Lounibos, and R. Lourenço de Oliveira. 2009. "Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro – are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?" Memórias do Instituto Oswaldo Cruz 104:1171–1176. doi: 10.1590/S0074-02762009000800015.

North, G. B., F. H. Lynch, F. D. Maharaj, C. A. Phillips, and W. T. Woodside. 2013. "Leaf Hydraulic Conductance for a Tank Bromeliad: Axial and Radial Pathways for Moving and Conserving Water." Frontiers in Plant Science. 4:78. doi: ten.3389/fpls.2013.00078.

O'Meara, K. F., One thousand. M. Cutwa, and L. F. Evans. 2003. "Bromeliad-Inhabiting Mosquitoes in South Florida: Native and Exotic Plants Differ in Species Composition." Journal of Vector Environmental 28:37–46.

Raban, R. R. 2006. "Studies of Aedes albopictus Oviposition and Larval Density, Development and Interactions with Wyeomyia spp. in Southern Florida." MSc thesis, Department of Entomology and Nematology, University of Florida, Gainesville.

Santos, C. B., G. R. Leite, and A. Falqueto. 2011. "Does (sic) Native Bromeliads Represent Of import Breeding Sites for Aedes aegypti in Urbanized Areas?" Neotropical Entomology forty:278–281. doi: 10.1590/s1519-566x2011000200019.

Wilke, A. B. B., C. Vasquez, P. J. Mauriello, and J. C. Beier. 2018. "Ornamental Bromeliads of Miami-Dade County, Florida Are Important Breeding Sites for Aedes aegypti (Diptera: Culicidae)" Parasites and Vectors 11:283–289. doi:10.1186/s13071-018-2866-9.

Xue, R-D, C. Lippi, and L. Drake. 2018. "Species Limerick of Mosquitoes and Invertebrates in Common Bromeliad Plant Axils (Family unit: Bromeliaceae) and the Plant Impacts on Survival of Vector Mosquito Aedes albopictus (Diptera: Culicidae)." China Tropical Medicine eighteen:6–10. doi: 10.13604/j.cnki.46-1064/r.2018.01.01.

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Source: https://edis.ifas.ufl.edu/publication/IN1343